I have always used mini-blind blades cut to 8 inches long. I write the name of the lily on the top of the "tag" on one side and at the bottom on the other so one is always under the dirt and will resist fading. The key to making sure the name will stay on the label is to use a Wishy-Washy Sharpie laundry marker. In my experience, these work much better than a regular Sharpies... Most likely because they are formulated to withstand being washed in a washer. Hope this has helped some! Oh, and I always put two tags per pot. In case one gets lost, the other will hopefully still be there...